#include<stdio.h>

int main()
{
    int killer = 0;
    //只有凶手说了假话，True == 3
    for (killer = 'a'; killer <= 'd'; killer++) {
        //判断几个True
        if ((killer != 'a') + (killer == 'c') + (killer == 'd') + (killer != 'd') == 3)
            printf("凶手是:%c", killer);
    }
    return 0;
}